The study’s authors also found that in the month and a half since its conclusion, there has been a shift away from Twitter toward platforms such as Instagram, Google+ and Snapchat.
Photograph: Eric Thayer/Reuters

Islamic State sympathisers in America prefer Twitter to any other social media platform and use avatars of black flags, green birds and lions – including the Detroit Lions NFL team – in their online propaganda, a study has shown.

Having a Twitter account suspended has become a “badge of honour” among US-based Isis supporters, researchers found, and they are adopting increasingly sophisticated techniques to circumvent the authorities in a “never-ending cat-and-mouse game”.

The report, Isis in America: From Retweets to Raqqa, published on Tuesday by George Washington University’s programme on extremism, analysed the social media accounts and legal documents of nearly 400 American followers of Isis. It found that 14% are female, the average age is 26, two in five are Muslim converts and more than half have travelled or attempted to travel abroad.

It also pointed to a thriving “American Isis Twitter scene”. During the six-month study, researchers monitored almost 300 accounts. The activity showed how social media plays a crucial role in their radicalisation and, at times, mobilisation to fight in Iraq and Syria.

Among the examples are newlywed couple Mohammad Oda Dakhlalla, 22, and his 19-year-old wife Jaelyn Delshaun Young. Dakhlalla, the son of a local imam, was about to start graduate school while Young, a police officer’s daughter and former school cheerleader, was studying chemistry. The couple lived a parallel life and planned a secret honeymoon: traveling to Syria to join Isis. In the early months of this year their radical musings on Twitter attracted the attention of the FBI, leading to their arrest at a small airport.

“It is an internet community with different roles and personalities, just like you have a community of Justin Bieber fans,” said Lorenzo Vidino, co-author of the report. “They’re getting better and better at it and there’s much more coordination than we thought. They get trolled so they have a list where the handles of trolls are shared.”

US authorities have estimated that several thousand Americans consume Isis propaganda online, the report notes. “American Isis activists and sympathisers are active on a variety of platforms, from open forums like Facebook, Google+ and Tumblr to more discreet messaging applications such as Kik, Telegram, surespot and the dark web. But Twitter is by far the platform of choice of this informal echo chamber.”

According to the study, a significant number of American Isis supporters use avatars of black flags, lions, and green birds – a scriptural reference from a hadith, or reported saying from the prophet Mohammad, that celebrates the virtues of martyrdom; jihadists term fallen comrades “green birds” to eulogise them as pious, faithful Muslims.

“A particularly clever account uses a picture of the Detroit Lions, combining a distinctly American pride in an NFL team and the popular Islamic symbol of bravery very frequently used by Isis supporters. Images, quotes and links to lectures of the deceased radical cleric Anwar al-Awlaki are favourites of the American Isis scene. Increasingly, photos of other Americans who have been arrested on terrorism charges, killed waging jihad abroad or were responsible for homegrown terrorist attacks are used as avatars.”

The Detroit Lions: an unwitting proxy for Isis support on Twitter. Photograph: PR

The study divides Isis supporters on Twitter into three categories: the “nodes” are the leading voices and generators of primary content, the “amplifiers” retweet material (it can be unclear whether they are real people or automated) and the “shout-outs” promote newly created accounts of suspended users.

“Shout-out accounts are a unique innovation and vital to the survival of the Isis online scene,” the report says. “They primarily introduce new, pro-Isis accounts to the community and promote newly created accounts of previously suspended users, allowing them to quickly regain their pre-suspension status. Although they tweet little substantive content, shout-out accounts tend to have the largest followings in the Twitter landscape and therefore play a pivotal role in the resilience of Isis’s Twitter community.”

Isis accounts are frequently suspended, but these have become “a badge of honour and a means by which an aspirant can bolster his or her legitimacy. In most suspension cases, a new (and often more than one) account with a variation of the previous username is created within hours.

“As American Isis supporters are continuously suspended from Twitter, creating a new account becomes increasingly difficult, leading some to turn to others for assistance. The user’s first tweet is often an image of the Twitter notification of suspension, proving that they are the owner of the previous account, along with a request for shout-outs. The new accounts are then retweeted by others, allowing the user to regain his or her previous online following.”

Vidino said on Monday the landscape is rapidly evolving and, even in the month and a half since his report was completed, there has been a shift away from Twitter towards platforms such as Instagram, Google+ and Snapchat. “It gives us a good snapshot,” he said of the report. “There’s no pretence it’s a perfect picture without flaws.”

As other studies have shown, most Isis followers in the US are American citizens – and young. Vidino added: “They are kids of their generation playing with avatars. Some change pictures almost on a daily basis. These are very suburban, normal American culture kind of kids with an Isis sympathy. It’s a hybrid identity.”

A spokesperson for Twitter declined to comment but pointed to its existing policies, including: “Users may not make threats of violence or promote violence, including threatening or promoting terrorism.”